The present invention relates to a credit card system, and particularly to one which includes a plurality of card readers at various locations enabling the subscribers to charge various items, involving the sale of a product or service, to their account at a central location.
The term "credit card", as used herein, is intended to include not only the usual credit cards whose users enjoy credit allowances, but also debit cards which are now finding widespread use to allow an immediate debiting to the user's account at the moment of the transaction.
More and more payments are carried out using credit cards (which term also includes debit cards, as noted above) insertable into card readers at various locations and communicating with a data base at a central location. However, such communication between local card readers and the central data base is relatively expensive, and the use of such a system for low value transactions is therefore normally not economically feasible. Thus, most vending machines do not allow credit card payments because of the relatively high expense, compared to the value of the transaction, involved in providing communication between the card reader and the central data base for payment approval. In addition, credit cards are not generally used to make payments for train tickets, toll charges, vending machines, etc., because of the time delay inherent in obtaining payment approval from the central data base, which time delay would cause undue congestion at the ticket gates, toll booths, vending machines, etc.